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Ekemezie CL, Melnikov SV. Hibernating ribosomes as drug targets? Front Microbiol 2024; 15:1436579. [PMID: 39135874 PMCID: PMC11317432 DOI: 10.3389/fmicb.2024.1436579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 06/24/2024] [Indexed: 08/15/2024] Open
Abstract
When ribosome-targeting antibiotics attack actively growing bacteria, they occupy ribosomal active centers, causing the ribosomes to stall or make errors that either halt cellular growth or cause bacterial death. However, emerging research indicates that bacterial ribosomes spend a considerable amount of time in an inactive state known as ribosome hibernation, in which they dissociate from their substrates and bind to specialized proteins called ribosome hibernation factors. Since 60% of microbial biomass exists in a dormant state at any given time, these hibernation factors are likely the most common partners of ribosomes in bacterial cells. Furthermore, some hibernation factors occupy ribosomal drug-binding sites - leading to the question of how ribosome hibernation influences antibiotic efficacy, and vice versa. In this review, we summarize the current state of knowledge on physical and functional interactions between hibernation factors and ribosome-targeting antibiotics and explore the possibility of using antibiotics to target not only active but also hibernating ribosomes. Because ribosome hibernation empowers bacteria to withstand harsh conditions such as starvation, stress, and host immunity, this line of research holds promise for medicine, agriculture, and biotechnology: by learning to regulate ribosome hibernation, we could enhance our capacity to manage the survival of microorganisms in dormancy.
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Affiliation(s)
- Chinenye L. Ekemezie
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Sergey V. Melnikov
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Medical School of Newcastle University, Newcastle upon Tyne, United Kingdom
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2
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Zhou K, Li CL, Zhang H, Suo BJ, Zhang YX, Ren XL, Wang YX, Mi CM, Ma LL, Zhou LY, Tian XL, Song ZQ. Minocycline in the eradication of Helicobacter pylori infection: A systematic review and meta-analysis. World J Gastroenterol 2024; 30:2354-2368. [PMID: 38813048 PMCID: PMC11130572 DOI: 10.3748/wjg.v30.i17.2354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/04/2024] [Accepted: 04/10/2024] [Indexed: 04/30/2024] Open
Abstract
BACKGROUND Difficulty in obtaining tetracycline, increased adverse reactions, and relatively complicated medication methods have limited the clinical application of the classic bismuth quadruple therapy. Therefore, the search for new alternative drugs has become one of the research hotspots. In recent years, minocycline, as a semisynthetic tetracycline, has demonstrated good potential for eradicating Helicobacter pylori (H. pylori) infection, but the systematic evaluation of its role remains lacking. AIM To explore the efficacy, safety, and compliance of minocycline in eradicating H. pylori infection. METHODS We comprehensively retrieved the electronic databases of PubMed, Embase, Web of Science, China National Knowledge Infrastructure, SinoMed, and Wanfang database as of October 30, 2023, and finally included 22 research reports on H. pylori eradication with minocycline-containing regimens as per the inclusion and exclusion criteria. The eradication rates of H. pylori were calculated using a fixed or a random effect model, and the heterogeneity and publication bias of the studies were measured. RESULTS The single-arm meta-analysis revealed that the minocycline-containing regimens achieved good overall H. pylori eradication rates, reaching 82.3% [95% confidence interval (CI): 79.7%-85.1%] in the intention-to-treat analysis and 90.0% (95%CI: 87.7%-92.4%) in the per-protocol analysis. The overall safety and compliance of the minocycline-containing regimens were good, demonstrating an overall incidence of adverse reactions of 36.5% (95%CI: 31.5%-42.2%). Further by traditional meta-analysis, the results showed that the minocycline-containing regimens were not statistically different from other commonly used eradication regimens in eradication rate and incidence of adverse effects. Most of the adverse reactions were mild to moderate and well-tolerated, and dizziness was relatively prominent in the minocycline-containing regimens (16%). CONCLUSION The minocycline-containing regimens demonstrated good efficacy, safety, and compliance in H. pylori eradication. Minocycline has good potential to replace tetracycline for eradicating H. pylori infection.
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Affiliation(s)
- Kai Zhou
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Cai-Ling Li
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Hua Zhang
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Bao-Jun Suo
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Yu-Xin Zhang
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Xin-Lu Ren
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Yu-Xin Wang
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Chang-Min Mi
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Ling-Ling Ma
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Li-Ya Zhou
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Xue-Li Tian
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
| | - Zhi-Qiang Song
- Department of Gastroenterology, Peking University Third Hospital, Beijing 100191, China
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3
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Hasanuzzaman M, Bang CS, Gong EJ. Antibiotic Resistance of Helicobacter pylori: Mechanisms and Clinical Implications. J Korean Med Sci 2024; 39:e44. [PMID: 38288543 PMCID: PMC10825452 DOI: 10.3346/jkms.2024.39.e44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 12/29/2023] [Indexed: 02/01/2024] Open
Abstract
Helicobacter pylori is a pathogenic bacterium associated with various gastrointestinal diseases, including chronic gastritis, peptic ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. The increasing rates of H. pylori antibiotic resistance and the emergence of multidrug-resistant strains pose significant challenges to its treatment. This comprehensive review explores the mechanisms underlying the resistance of H. pylori to commonly used antibiotics and the clinical implications of antibiotic resistance. Additionally, potential strategies for overcoming antibiotic resistance are discussed. These approaches aim to improve the treatment outcomes of H. pylori infections while minimizing the development of antibiotic resistance. The continuous evolution of treatment perspectives and ongoing research in this field are crucial for effectively combating this challenging infection.
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Affiliation(s)
- Md Hasanuzzaman
- Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea
| | - Chang Seok Bang
- Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea
| | - Eun Jeong Gong
- Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
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4
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Ng HY, Leung WK, Cheung KS. Antibiotic Resistance, Susceptibility Testing and Stewardship in Helicobacter pylori Infection. Int J Mol Sci 2023; 24:11708. [PMID: 37511471 PMCID: PMC10380565 DOI: 10.3390/ijms241411708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/12/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
Despite the declining trend of Helicobacter pylori (H. pylori) prevalence around the globe, ongoing efforts are still needed to optimize current and future regimens in view of the increasing antibiotic resistance. The resistance of H. pylori to different antibiotics is caused by different molecular mechanisms, and advancements in sequencing technology have come a far way in broadening our understanding and in facilitating the testing of antibiotic susceptibility to H. pylori. In this literature review, we give an overview of the molecular mechanisms behind resistance, as well as discuss and compare different antibiotic susceptibility tests based on the latest research. We also discuss the principles of antibiotic stewardship and compare the performance of empirical therapies based on up-to-date resistance patterns and susceptibility-guided therapies in providing effective H. pylori treatment. Studies and clinical guidelines should ensure that the treatment being tested or recommended can reliably achieve a pre-agreed acceptable level of eradication rate and take into account the variations in antibiotic resistance across populations. Local, regional and international organizations must work together to establish routine antibiotic susceptibility surveillance programs and enforce antibiotic stewardship in the treatment of H. pylori, so that it can be managed in a sustainable and efficient manner.
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Affiliation(s)
- Ho-Yu Ng
- School of Clinical Medicine, The University of Hong Kong, Hong Kong, China
| | - Wai K Leung
- Department of Medicine, School of Clinical Medicine, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China
| | - Ka-Shing Cheung
- Department of Medicine, School of Clinical Medicine, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China
- Department of Medicine, The University of Hong Kong-Shenzhen Hospital, Shenzhen 518053, China
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Ansari S, Yamaoka Y. Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance. Clin Microbiol Rev 2022; 35:e0025821. [PMID: 35404105 PMCID: PMC9491184 DOI: 10.1128/cmr.00258-21] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.
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Affiliation(s)
- Shamshul Ansari
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu City, Oita, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu City, Oita, Japan
- Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, Texas, USA
- Institute of Tropical Disease, Universitas Airlangga, Surabaya, Indonesia
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6
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A Survey of Helicobacter pylori Antibiotic-Resistant Genotypes and Strain Lineages by Whole-Genome Sequencing in China. Antimicrob Agents Chemother 2022; 66:e0218821. [PMID: 35652644 PMCID: PMC9211431 DOI: 10.1128/aac.02188-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Antibiotic resistance is the most important factor leading to failed Helicobacter pylori eradication therapy, and personalized treatment based on antibiotic susceptibility is becoming increasingly important. To strengthen the understanding of antibiotic genotypic resistance of H. pylori and identify new antibiotic resistance loci, in this study, we identified phenotypic resistance information for 60 clinical isolates and compared the concordance of phenotypic and genotypic resistance using whole-genome sequencing (WGS). Clarithromycin and levofloxacin genotypic resistance was in almost perfect concordance with phenotypic resistance, with kappa coefficients of 0.867 and 0.833, respectively. All strains with the R16H/C mutation and truncation in rdxA were metronidazole resistant, with 100% specificity. For other genes of concern, at least one phenotypically sensitive strain had a previous mutation related to antibiotic resistance. Moreover, we found that the A1378G mutation of HP0399 and the A149G mutation of FabH might contribute to tetracycline resistance and multidrug resistance, respectively. Overall, the inference of resistance to clarithromycin and levofloxacin from genotypic resistance is reliable, and WGS has been very helpful in discovering novel H. pylori resistance loci. In addition, WGS has also enhanced our study of strain lineages, providing new ways to understand resistance information and mechanisms.
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7
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Impact of 16S rRNA Single Nucleotide Polymorphisms on Mycoplasma genitalium Organism Load with Doxycycline Treatment. Antimicrob Agents Chemother 2022; 66:e0024322. [PMID: 35420491 DOI: 10.1128/aac.00243-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Doxycycline targets the 16S rRNA and is widely used for the treatment of sexually transmitted infections. While it is not highly effective at eradicating Mycoplasma genitalium infections, it can reduce organism load. The aim of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the 16S rRNA gene of M. genitalium and change in organism load. M. genitalium samples were collected from 56 men prior to commencing doxycycline and at a median of 13 of 14 doses. These were sequenced for the 16S rRNA, and the association between 16S rRNA SNPs and change in organism load was determined. 16S rRNA sequences were available for 52/56 (92.9%) M. genitalium-infected men, of which 20 (38.5%) had an undetectable load, 26 (50.0%) had a decrease in M. genitalium load (median change of 105-fold), and 6 (11.5%) had an increase in load (median change of 5-fold). The most common SNPs identified were A742G (10/52 [19.2%]), GG960-961TT/C (7/52 [13.5%]), and C1435T (28/52 [53.8%]) (M. genitalium numbering). None were associated with a change in organism load (P = 0.76, 0.16, and 0.98, respectively). Using pooled published data from 28 isolates, no clear relationship between the SNPs and doxycycline MIC was identified. In conclusion, the low efficacy of doxycycline against M. genitalium does not appear to be due to variation in the 16S rRNA gene.
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Zurita J, Sevillano G, Paz Y Miño A, Zurita-Salinas C, Peñaherrera V, Echeverría M, Navarrete H. Mutations associated with Helicobacter pylori antimicrobial resistance in the Ecuadorian population. J Appl Microbiol 2021; 132:2694-2704. [PMID: 34856035 DOI: 10.1111/jam.15396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 11/19/2021] [Accepted: 11/28/2021] [Indexed: 11/30/2022]
Abstract
AIMS We described the presence of Helicobacter pylori (HP) and estimated the prevalence of primary and secondary resistance using molecular detection in gastric biopsies of Ecuadorian patients. METHODS AND RESULTS 66.7% (238/357) of the patients demonstrated the presence of HP using CerTest qPCR. Of these, 69.79% (104/149) were without previous HP eradication treatment and 64.42% (134/208) with prior HP eradication treatment. The mutation-associated resistance rate for clarithromycin was 33.64% (primary resistance) and 32.82% (secondary resistance), whereas that in levofloxacin the primary and secondary resistance was 37.38% and 42%, respectively. For tetracycline and rifabutin, primary and secondary resistance was 0%. Primary and secondary resistance for metronidazole and amoxicillin could not be evaluated by genotypic methods (PCR and sequencing). CONCLUSIONS The analysis of mutations in gyrA, 23S rRNA and 16S rRNA is useful to detect bacterial resistance as a guide for eradication therapy following failure of the first-line regimen. SIGNIFICANCE AND IMPACT OF THE STUDY This study carried out in an Ecuadorian population indicates that the resistance of HP to first-line antibiotics is high, which may contribute to the high rates of treatment failure, and other treatment alternatives should be considered.
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Affiliation(s)
- Jeannete Zurita
- Servicio de Microbiologia y Tuberculosis, Hospital Vozandes, Quito, Ecuador.,Facultad de Medicina, Pontificia Universidad Católica del Ecuador, Quito, Ecuador.,Unidad de Investigaciones en Biomedicina, Zurita & Zurita Laboratorios, Quito, Ecuador
| | - Gabriela Sevillano
- Unidad de Investigaciones en Biomedicina, Zurita & Zurita Laboratorios, Quito, Ecuador
| | - Ariane Paz Y Miño
- Unidad de Investigaciones en Biomedicina, Zurita & Zurita Laboratorios, Quito, Ecuador
| | - Camilo Zurita-Salinas
- Unidad de Investigaciones en Biomedicina, Zurita & Zurita Laboratorios, Quito, Ecuador
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- Servicio de Gastroenterología, Hospital Vozandes, Quito, Ecuador
| | - Hugo Navarrete
- Facultad de Ciencias Exactas y Naturales, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
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9
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Tshibangu-Kabamba E, Yamaoka Y. Helicobacter pylori infection and antibiotic resistance - from biology to clinical implications. Nat Rev Gastroenterol Hepatol 2021; 18:613-629. [PMID: 34002081 DOI: 10.1038/s41575-021-00449-x] [Citation(s) in RCA: 195] [Impact Index Per Article: 65.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/31/2021] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori is a major human pathogen for which increasing antibiotic resistance constitutes a serious threat to human health. Molecular mechanisms underlying this resistance have been intensively studied and are discussed in this Review. Three profiles of resistance - single drug resistance, multidrug resistance and heteroresistance - seem to occur, probably with overlapping fundamental mechanisms and clinical implications. The mechanisms that have been most studied are related to mutational changes encoded chromosomally and disrupt the cellular activity of antibiotics through target-mediated mechanisms. Other biological attributes driving drug resistance in H. pylori have been less explored and this could imply more complex physiological changes (such as impaired regulation of drug uptake and/or efflux, or biofilm and coccoid formation) that remain largely elusive. Resistance-related attributes deployed by the pathogen cause treatment failures, diagnostic difficulties and ambiguity in clinical interpretation of therapeutic outcomes. Subsequent to the increasing antibiotic resistance, a substantial drop in H. pylori treatment efficacy has been noted globally. In the absence of an efficient vaccine, enhanced efforts are needed for setting new treatment strategies and for a better understanding of the emergence and spread of drug-resistant bacteria, as well as for improving diagnostic tools that can help optimize current antimicrobial regimens.
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Affiliation(s)
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Oita, Japan. .,Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, TX, USA.
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10
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Gong RJ, Xu CX, Li H, Liu XM. Polymerase chain reaction-based tests for detecting Helicobacter pylori clarithromycin resistance in stool samples: A meta-analysis. World J Clin Cases 2021; 9:133-147. [PMID: 33511178 PMCID: PMC7809662 DOI: 10.12998/wjcc.v9.i1.133] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/07/2020] [Accepted: 11/14/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Helicobacter pylori (H. pylori) infection is closely associated with the etiology of a variety of gastric diseases. The effective eradication of H. pylori infection has been shown to reduce the incidence of gastric carcinoma. However, the rate of H. pylori eradication has significantly declined due to its increasing resistance to antibiotics, especially to clarithromycin. Therefore, the detection of clarithromycin resistance is necessary prior to the treatment of H. pylori. Although many studies have been conducted on the use of polymerase chain reaction (PCR)-based tests to detect clarithromycin resistance in stool samples, no accurate data on the feasibility of these tests are available. Here, we performed a meta-analysis to assess the feasibility of these noninvasive tests.
AIM To evaluate the reliability of PCR-based tests for detecting H. pylori clarithromycin resistance in stool samples.
METHODS We searched PubMed, Medline, Embase, and other databases for articles that evaluated the value of the PCR analysis of stool samples for detecting the resistance of H. pylori to clarithromycin. We collected cross-sectional studies that met the inclusion criteria. Diagnostic accuracy measures were pooled using a random-effects model. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Subgroup analysis was also conducted according to PCR type, purification technique, reference standard, mutation site, sample weight, number of patients, and age group, and the clinical utility of diagnostic tests was evaluated using the Likelihood Ratio Scatter Graph.
RESULTS Out of the 1818 identified studies, only 11 met the eligibility criteria, with a total of 592 patients assessed. A meta-analysis of the random-effect model showed that PCR-based analysis of stool samples had high diagnostic accuracy for detecting clarithromycin resistance in patients infected with H. pylori. The combined sensitivity was 0.91 [95% confidence interval (CI): 0.83-0.95], Q = 30.34, and I2 = 67.04, and the combined specificity was 0.97 (95%CI: 0.62-1.00), Q = 279.54, and I2 = 96.42. The likelihood ratio for a positive test was 33.25 (95%CI: 1.69-652.77), and that for a negative test was 0.10 (95%CI: 0.05-0.18), with an area under the curve of 0.94. The diagnostic odds ratio was 347.68 (95%CI: 17.29-6991.26). There was significant statistical heterogeneity, and the sub-analyses showed significant differences in the number of patients, sample weight, purification methods, PCR types, mutation points, and reference standards. The included studies showed no risk of publication bias.
CONCLUSION PCR-based tests on stool samples have high diagnostic accuracy for detecting H. pylori clarithromycin resistance.
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Affiliation(s)
- Ren-Jie Gong
- Department of Gastroenterology, The Third Xiangya Hospital of Central South University, Changsha 410013, Hunan Province, China
| | - Can-Xia Xu
- Department of Gastroenterology, The Third Xiangya Hospital of Central South University, Changsha 410013, Hunan Province, China
| | - Huan Li
- Department of Gastroenterology, The Third Xiangya Hospital of Central South University, Changsha 410013, Hunan Province, China
| | - Xiao-Ming Liu
- Department of Gastroenterology, The Third Xiangya Hospital of Central South University, Changsha 410013, Hunan Province, China
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11
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Molecular Phylogenetic Analysis of 16S rRNA Sequences Identified Two Lineages of Helicobacter pylori Strains Detected from Different Regions in Sudan Suggestive of Differential Evolution. Int J Microbiol 2020; 2020:8825718. [PMID: 33178282 PMCID: PMC7609147 DOI: 10.1155/2020/8825718] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/30/2020] [Accepted: 10/01/2020] [Indexed: 12/22/2022] Open
Abstract
Background Helicobacter pylori (H. pylori) is ubiquitous among humans and one of the best-studied examples of an intimate association between bacteria and humans. Phylogeny and Phylogeography of H. pylori strains are known to mirror human migration patterns and reflect significant demographic events in human prehistory. In this study, we analyzed the molecular evolution of H. pylori strains detected from different tribes and regions of Sudan using 16S rRNA gene and the phylogenetic approach. Materials and methods. A total of 75 gastric biopsies were taken from patients who had been referred for endoscopy from different regions of Sudan. The DNA extraction was performed by using the guanidine chloride method. Two sets of primers (universal and specific for H. pylori) were used to amplify the 16S ribosomal gene. Sanger sequencing was applied, and the resulted sequences were matched with the sequences of the National Center for Biotechnology Information (NCBI) nucleotide database. The evolutionary aspects were analyzed using MEGA7 software. Results Molecular detection of H. pylori has shown that 28 (37.33%) of the patients were positive for H. pylori and no significant differences were found in sociodemographic characteristics, endoscopy series, and H. pylori infection. Nucleotide variations were observed at five nucleotide positions (positions 219, 305, 578, 741, and 763-764), and one insertion mutation (750_InsC_751) was present in sixty-seven percent (7/12) of our strains. These six mutations were detected in regions of the 16S rRNA not closely associated with either tetracycline or tRNA binding sites; 66.67% of them were located in the central domain of 16S rRNA. The phylogenetic analysis of 16S rRNA sequences identified two lineages of H. pylori strains detected from different regions in Sudan. The presence of Sudanese H. pylori strains resembling Hungarian H. pylori strains could reflect the migration of Hungarian people to Sudan or vice versa. Conclusion This finding emphasizes the significance of studying the phylogeny of H. pylori strains as a discriminatory tool to mirror human migration patterns. In addition, the 16S rRNA gene amplification method was found useful for bacterial identification and phylogeny.
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12
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Fang LX, Chen C, Cui CY, Li XP, Zhang Y, Liao XP, Sun J, Liu YH. Emerging High-Level Tigecycline Resistance: Novel Tetracycline Destructases Spread via the Mobile Tet(X). Bioessays 2020; 42:e2000014. [PMID: 32567703 DOI: 10.1002/bies.202000014] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/18/2020] [Indexed: 12/20/2022]
Abstract
Antibiotic resistance in bacteria has become a great threat to global public health. Tigecycline is a next-generation tetracycline that is the final line of defense against severe infections by pan-drug-resistant bacterial pathogens. Unfortunately, this last-resort antibiotic has been challenged by the recent emergence of the mobile Tet(X) orthologs that can confer high-level tigecycline resistance. As it is reviewed here, these novel tetracycline destructases represent a growing threat to the next-generation tetracyclines, and a basic framework for understanding the molecular epidemiology and resistance mechanisms of them is presented. However, further large-scale epidemiological and functional studies are urgently needed to better understand the prevalence and dissemination of these newly discovered Tet(X) orthologs among Gram-negative bacteria in both human and veterinary medicine.
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Affiliation(s)
- Liang-Xing Fang
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, 510642, China.,Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China
| | - Chong Chen
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, 510642, China
| | - Chao-Yue Cui
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, 510642, China
| | - Xing-Ping Li
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, 510642, China
| | - Yan Zhang
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, 510642, China
| | - Xiao-Ping Liao
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, 510642, China.,Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China
| | - Jian Sun
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, 510642, China.,Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China
| | - Ya-Hong Liu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, 510642, China.,Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, 510642, China
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13
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Zanotti G, Cendron L. Structural Aspects of Helicobacter pylori Antibiotic Resistance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:227-241. [PMID: 31016632 DOI: 10.1007/5584_2019_368] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Resistance to antibiotics of Helicobacter pylori infections is growing rapidly together with the need for more potent antimicrobials or novel strategies to recover the efficacy of the existing ones. Despite the main mechanisms according to which H. pylori acquires resistance are common to other microbial infections affecting humans, H. pylori has its own peculiarities, mostly due to the unique conditions experienced by the bacterium in the gastric niche. Possibly the most used of the antibiotics for H. pylori are those molecules that bind to the ribosome or to the DNA and RNA machinery, and in doing so they interfere with protein synthesis. Another important class is represented by molecules that binds to some enzyme essential for the bacterium survival, as in the case of enzymes involved in the bacterial wall biosynthesis. The mechanism used by the bacterium to fight antibiotics can be grouped in three classes: (i) mutations of some key residues in the protein that binds the inhibitor, (ii) regulation of the efflux systems or of the membrane permeability in order to reduce the uptake of the antibiotic, and (iii) other more complex indirect effects. Interestingly, the production of enzymes that degrade the antibiotics (as in the case of β-lactamases in many other bacteria) has not been clearly detected in H. pylori. The structural aspects of resistance players have not been object of extensive studies yet and the structure of very few H. pylori proteins involved in the resistance mechanisms are determined till now. Models of the proteins that play key roles in reducing antimicrobials susceptibility and their implications will be discussed in this chapter.
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Affiliation(s)
- Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padua, Padua, Italy.
| | - Laura Cendron
- Department of Biology, University of Padua, Padua, Italy
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14
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Screening for ESBL producing bacterial isolates of agricultural soil and profiling for multidrug resistance. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.aasci.2018.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Wang YH, Li Z, Wang L, Zhu-Ge LY, Zhao RL, Wu S, Wang Y, An Y, Xie Y. A systematic review and meta-analysis of genotypic methods for detecting antibiotic resistance in Helicobacter pylori. Helicobacter 2018; 23:e12467. [PMID: 29405526 DOI: 10.1111/hel.12467] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Antibiotic susceptibility testing is essential for tailored treatments to cure Helicobacter pylori (H. pylori) infection. However, phenotypic methods have some limitations. OBJECTIVES To evaluate the feasibility of genotypic detection methods compared with phenotypic detection methods using samples taken from H. pylori-infected patients. METHODS Literature searches were conducted in the following databases (from January 2000 to November 2016): PubMed, Embase, the Cochrane Library, and Web of Science. A meta-analysis and systematic review was performed for studies that compared genotypic methods with phenotypic methods for the detection of H. pylori antibiotic susceptibility. RESULTS This meta-analysis showed that the pooled sensitivity, specificity, and diagnostic odds ratio (DOR) for the A2142G/C and/or A2143G combination for the detection of clarithromycin resistance in the strain samples were 0.97 (95% CI: 0.94-0.99), 1.00 (95% CI: 0.99-1.00), and 13 742 (95% CI: 1708-110 554), respectively. The pooled sensitivity, specificity, and DOR for the A2142G/C and/or A2143G combination for the detection of clarithromycin resistance in biopsy samples were 0.96 (95% CI: 0.90-0.99), 0.96 (95% CI: 0.91-0.99), and 722 (95% CI: 117-4443), respectively. The summarized sensitivity, specificity, and DOR value for the ability of the genotypic methods to detect quinolone resistance in biopsy specimens were 0.97 (95% CI: 0.87-0.99), 0.99 (95% CI: 0.92-1.00), and 6042 (95% CI: 486-75 143), respectively. CONCLUSION The genotypic detection methods were reliable for the diagnosis of clarithromycin and quinolone resistance in the strain and biopsy specimens. The A2142G/C and/or A2143G combination had the best sensitivity and specificity for the detection of clarithromycin resistance.
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Affiliation(s)
- You-Hua Wang
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Zhen Li
- Department of Medical College, Nanchang University, Nanchang, Jiangxi Province, China
| | - Le Wang
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China.,Jiangxi Provincial Key Laboratory of Translational Medicine and Oncology, Jiangxi Cancer Hospital, Nanchang, Jiangxi Province, China
| | - Li-Ya Zhu-Ge
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Ru-Lin Zhao
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China.,Department of Medical College, Nanchang University, Nanchang, Jiangxi Province, China
| | - Shuang Wu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Ya Wang
- Department of Medical College, Nanchang University, Nanchang, Jiangxi Province, China
| | - Ying An
- Department of Medical College, Nanchang University, Nanchang, Jiangxi Province, China
| | - Yong Xie
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China
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Loss of Methyltransferase Function and Increased Efflux Activity Leads to Doxycycline Resistance in Burkholderia pseudomallei. Antimicrob Agents Chemother 2017; 61:AAC.00268-17. [PMID: 28348161 DOI: 10.1128/aac.00268-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 03/18/2017] [Indexed: 01/15/2023] Open
Abstract
The soil-dwelling bacterium Burkholderia pseudomallei is the causative agent of the potentially fatal disease melioidosis. The lack of a vaccine toward B. pseudomallei means that melioidosis treatment relies on prolonged antibiotic therapy, which can last up to 6 months in duration or longer. Due to intrinsic resistance, few antibiotics are effective against B. pseudomallei The lengthy treatment regimen required increases the likelihood of resistance development, with subsequent potentially fatal relapse. Doxycycline (DOX) has historically played an important role in the eradication phase of melioidosis treatment. Both primary and acquired DOX resistances have been documented in B. pseudomallei; however, the molecular mechanisms underpinning DOX resistance have remained elusive. Here, we identify and functionally characterize the molecular mechanisms conferring acquired DOX resistance in an isogenic B. pseudomallei pair. Two synergistic mechanisms were identified. The first mutation occurred in a putative S-adenosyl-l-methionine-dependent methyltransferase (encoded by BPSL3085), which we propose leads to altered ribosomal methylation, thereby decreasing DOX binding efficiency. The second mutation altered the function of the efflux pump repressor gene, amrR, resulting in increased expression of the resistance-nodulation-division efflux pump, AmrAB-OprA. Our findings highlight the diverse mechanisms by which B. pseudomallei can become resistant to antibiotics used in melioidosis therapy and the need for resistance monitoring during treatment regimens, especially in patients with prolonged or recrudesced positive cultures for B. pseudomallei.
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Berg DE. Julian Davies and the discovery of kanamycin resistance transposon Tn5. J Antibiot (Tokyo) 2016; 70:339-346. [PMID: 27731334 DOI: 10.1038/ja.2016.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 08/28/2016] [Accepted: 08/31/2016] [Indexed: 11/09/2022]
Abstract
This paper recounts some of my fond memories of a collaboration between Julian Davies and myself that started in 1974 in Geneva and that led to our serendipitous discovery of the bacterial kanamycin resistance transposon Tn5, and aspects of the lasting positive impact of our interaction and discovery on me and the community. Tn5 was one of the first antibiotic resistance transposons to be found. Its analysis over the ensuing decades provided valuable insights into mechanisms and control of transposition, and led to its use as a much-valued tool in diverse areas of molecular genetics, as also will be discussed here.
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Affiliation(s)
- Douglas E Berg
- Division of Infectious Disease, Department of Medicine, University of California San Diego, La Jolla, CA, USA
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18
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Hu Y, Zhang M, Lu B, Dai J. Helicobacter pylori and Antibiotic Resistance, A Continuing and Intractable Problem. Helicobacter 2016; 21:349-63. [PMID: 26822340 DOI: 10.1111/hel.12299] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori, a human pathogen with a high global prevalence, is the causative pathogen for multiple gastrointestinal diseases, especially chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric malignancies. Antibiotic therapies remain the mainstay for H. pylori eradication; however, this strategy is hampered by the emergence and spread of H. pylori antibiotic resistance. Exploring the mechanistic basis of this resistance is becoming one of the major research questions in contemporary biomedical research, as such knowledge could be exploited to devise novel rational avenues for counteracting the existing resistance and devising strategies to avoid the development of a novel anti-H. pylori medication. Encouragingly, important progress in this field has been made recently. Here, we attempt to review the current state and progress with respect to the molecular mechanism of antibiotic resistance for H. pylori. A picture is emerging in which mutations of various genes in H. pylori, resulting in decreased membrane permeability, altered oxidation-reduction potential, and a more efficient efflux pump system. The increased knowledge on these mechanisms produces hope that antibiotic resistance in H. pylori can ultimately be countered.
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Affiliation(s)
- Yue Hu
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Meng Zhang
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Bin Lu
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China.
| | - Jinfeng Dai
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
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rRNA Binding Sites and the Molecular Mechanism of Action of the Tetracyclines. Antimicrob Agents Chemother 2016; 60:4433-41. [PMID: 27246781 DOI: 10.1128/aac.00594-16] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The tetracycline antibiotics are known to be effective in the treatment of both infectious and noninfectious disease conditions. The 16S rRNA binding mechanism currently held for the antibacterial action of the tetracyclines does not explain their activity against viruses, protozoa that lack mitochondria, and noninfectious conditions. Also, the mechanism by which the tetracyclines selectively inhibit microbial protein synthesis against host eukaryotic protein synthesis despite conservation of ribosome structure and functions is still questionable. Many studies have investigated the binding of the tetracyclines to the 16S rRNA using the small ribosomal subunit of different bacterial species, but there seems to be no agreement between various reports on the exact binding site on the 16S rRNA. The wide range of activity of the tetracyclines against a broad spectrum of bacterial pathogens, viruses, protozoa, and helminths, as well as noninfectious conditions, indicates a more generalized effect on RNA. In the light of recent evidence that the tetracyclines bind to various synthetic double-stranded RNAs (dsRNAs) of random base sequences, suggesting that the double-stranded structures may play a more important role in the binding of the tetracyclines to RNA than the specific base pairs, as earlier speculated, it is imperative to consider possible alternative binding modes or sites that could help explain the mechanisms of action of the tetracyclines against various pathogens and disease conditions.
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20
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Resistance mutations generate divergent antibiotic susceptibility profiles against translation inhibitors. Proc Natl Acad Sci U S A 2016; 113:8188-93. [PMID: 27382179 DOI: 10.1073/pnas.1605127113] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Mutations conferring resistance to translation inhibitors often alter the structure of rRNA. Reduced susceptibility to distinct structural antibiotic classes may, therefore, emerge when a common ribosomal binding site is perturbed, which significantly reduces the clinical utility of these agents. The translation inhibitors negamycin and tetracycline interfere with tRNA binding to the aminoacyl-tRNA site on the small 30S ribosomal subunit. However, two negamycin resistance mutations display unexpected differential antibiotic susceptibility profiles. Mutant U1060A in 16S Escherichia coli rRNA is resistant to both antibiotics, whereas mutant U1052G is simultaneously resistant to negamycin and hypersusceptible to tetracycline. Using a combination of microbiological, biochemical, single-molecule fluorescence transfer experiments, and X-ray crystallography, we define the specific structural defects in the U1052G mutant 70S E. coli ribosome that explain its divergent negamycin and tetracycline susceptibility profiles. Unexpectedly, the U1052G mutant ribosome possesses a second tetracycline binding site that correlates with its hypersusceptibility. The creation of a previously unidentified antibiotic binding site raises the prospect of identifying similar phenomena in antibiotic-resistant pathogens in the future.
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21
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Gaillard T, Madamet M, Pradines B. Tetracyclines in malaria. Malar J 2015; 14:445. [PMID: 26555664 PMCID: PMC4641395 DOI: 10.1186/s12936-015-0980-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/02/2015] [Indexed: 11/12/2022] Open
Abstract
Malaria, a parasite vector-borne disease, is one of the greatest health threats in tropical regions, despite the availability of malaria chemoprophylaxis. The emergence and rapid extension of Plasmodium falciparum resistance to various anti-malarial drugs has gradually limited the number of potential malaria therapeutics available to clinicians. In this context, doxycycline, a synthetically derived tetracycline, constitutes an interesting alternative for malaria treatment and prophylaxis. Doxycycline is a slow-acting blood schizontocidal agent that is highly effective at preventing malaria. In areas with chloroquine and multidrug-resistant P. falciparum parasites, doxycycline has already been successfully used in combination with quinine to treat malaria, and it has been proven to be effective and well-tolerated. Although not recommended for pregnant women and children younger than 8 years of age, severe adverse effects are rarely reported. In addition, resistance to doxycycline is rarely described. Prophylactic and clinical failures of doxycycline have been associated with both inadequate doses and poor patient compliance. The effects of tetracyclines on parasites are not completely understood. A better comprehension of the mechanisms underlying drug resistance would facilitate the identification of molecular markers of resistance to predict and survey the emergence of resistance.
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Affiliation(s)
- Tiphaine Gaillard
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM 63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, Marseille, France. .,Fédération des Laboratoires, Hôpital d'Instruction des Armées Saint Anne, Toulon, France.
| | - Marylin Madamet
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM 63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, Marseille, France. .,Equipe Résidente de Recherche en Infectiologie Tropicale, Institut de Recherche Biomédicale des Armées, Hôpital d'Instruction des Armées, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France.
| | - Bruno Pradines
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM 63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France. .,Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France.
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22
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Gaillard T, Wurtz N, Houzé S, Sriprawat K, Wangsing C, Hubert V, Lebras J, Nosten F, Briolant S, Pradines B. Absence of association between Plasmodium falciparum small sub-unit ribosomal RNA gene mutations and in vitro decreased susceptibility to doxycycline. Malar J 2015; 14:348. [PMID: 26377329 PMCID: PMC4574345 DOI: 10.1186/s12936-015-0878-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 08/29/2015] [Indexed: 02/16/2023] Open
Abstract
Background Doxycycline is an antibiotic used in combination with quinine or artesunate for malaria treatment or alone for malaria chemoprophylaxis. Recently, one prophylactic failure has been reported, and several studies have highlighted in vitro doxycycline decreased susceptibility in Plasmodium falciparum isolates from different areas. The genetic markers that contribute to detecting and monitoring the susceptibility of P. falciparum to doxycycline, the pfmdt and pftetQ genes, have recently been identified. However, these markers are not sufficient to explain in vitro decreased susceptibility of P. falciparum to doxycycline. In this paper, the association between polymorphism of the small sub-unit ribosomal RNA apicoplastic gene pfssrRNA (PFC10_API0057) and in vitro susceptibilities of P. falciparum isolates to doxycycline were investigated. Methods Doxycycline IC50 determinations using the hypoxanthine uptake inhibition assay were performed on 178 African and Thai P. falciparum isolates. The polymorphism of pfssrRNA was investigated in these samples by standard PCR followed by sequencing. Results No point mutations were found in pfssrRNA in the Thai or African isolates, regardless of the determined IC50 values. Conclusions The pfssrRNA gene is not associated with in vitro decreased susceptibility of P. falciparum to doxycycline. Identifying new in vitro molecular markers associated with reduced susceptibility is needed, to survey the emergence of doxycycline resistance.
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Affiliation(s)
- Tiphaine Gaillard
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Fédération des Laboratoires, Hôpital d'Instruction des Armées Saint Anne, Toulon, France.
| | - Nathalie Wurtz
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France.
| | - Sandrine Houzé
- Laboratoire de Parasitologie-Mycologie, Centre National de Référence du Paludisme, APHP, Hôpital Bichat-Claude Bernard, Paris, France. .,IRD UMR216, Mère et enfant face aux infections tropicales, Paris, France. .,PRES Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Paris, France.
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sod, Thailand.
| | - Chirapat Wangsing
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sod, Thailand.
| | - Véronique Hubert
- Laboratoire de Parasitologie-Mycologie, Centre National de Référence du Paludisme, APHP, Hôpital Bichat-Claude Bernard, Paris, France. .,PRES Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Paris, France.
| | - Jacques Lebras
- Laboratoire de Parasitologie-Mycologie, Centre National de Référence du Paludisme, APHP, Hôpital Bichat-Claude Bernard, Paris, France. .,IRD UMR216, Mère et enfant face aux infections tropicales, Paris, France. .,PRES Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Paris, France.
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sod, Thailand. .,Centre for Tropical Medicine, University of Oxford, Oxford, UK.
| | - Sébastien Briolant
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Direction Inter-Armées du Service de Santé, Cayenne, French Guiana. .,Laboratoire de Parasitologie, Institut Pasteur de la Guyane, Cayenne, French Guiana.
| | - Bruno Pradines
- Unité de Parasitologie, Département d'Infectiologie de Terrain, Institut de Recherche Biomédicale des Armées, Marseille, France. .,Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Aix Marseille Université, UM 63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France. .,Centre National de Référence du Paludisme, Marseille, France. .,Unité de Parasitologie et d'Entomologie, Département des Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France.
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Mégraud F, Bénéjat L, Ontsira Ngoyi EN, Lehours P. Molecular Approaches to Identify Helicobacter pylori Antimicrobial Resistance. Gastroenterol Clin North Am 2015; 44:577-96. [PMID: 26314669 DOI: 10.1016/j.gtc.2015.05.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Antimicrobial susceptibility testing is needed to adapt Helicobacter pylori treatment to obtain the best results. Beside the standard phenotypic methods, molecular methods are increasingly used. The value of these molecular tests is that they are quick, independent of the transport conditions, easy to standardize, and commercial kits are available. In this article, these methods are reviewed, focusing on the determination of H pylori resistance to macrolides and fluoroquinolones, and mentioning also the methods used for tetracycline and rifampin.
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Affiliation(s)
- Francis Mégraud
- Bacteriology Laboratory, INSERM U853, University of Bordeaux, Bordeaux F-33000, France.
| | - Lucie Bénéjat
- Bacteriology Laboratory, INSERM U853, University of Bordeaux, Bordeaux F-33000, France
| | | | - Philippe Lehours
- Bacteriology Laboratory, INSERM U853, University of Bordeaux, Bordeaux F-33000, France
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Ontsira Ngoyi EN, Atipo Ibara BI, Moyen R, Ahoui Apendi PC, Ibara JR, Obengui O, Ossibi Ibara RB, Nguimbi E, Niama RF, Ouamba JM, Yala F, Abena AA, Vadivelu J, Goh KL, Menard A, Benejat L, Sifre E, Lehours P, Megraud F. Molecular Detection of Helicobacter pylori and its Antimicrobial Resistance in Brazzaville, Congo. Helicobacter 2015; 20:316-20. [PMID: 25585658 DOI: 10.1111/hel.12204] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACK GROUND Helicobacter pylori infection is involved in several gastroduodenal diseases which can be cured by antimicrobial treatment. The aim of this study was to determine the prevalence of H. pylori infection and its bacterial resistance to clarithromycin, fluoroquinolones, and tetracycline in Brazzaville, Congo, by using molecular methods. MATERIAL AND METHODS A cross- sectional study was carried out between September 2013 and April 2014. Biopsy specimens were obtained from patients scheduled for an upper gastrointestinal endoscopy and were sent to the French National Reference Center for Campylobacters and Helicobacters where they were tested by molecular methods for detection of H. pylori and clarithromycin resistance by real-time PCR using a fluorescence resonance energy transfer-melting curve analysis (FRET-MCA) protocol, for detection of tetracycline resistance by real-time PCR on 16S rRNA genes (rrnA and rrnB), for detection of point mutations in the quinolone resistance-determining regions (QRDR) of H. pylori gyrA gene, associated with resistance to quinolones, by PCR and sequencing. RESULTS This study showed a high H. pylori prevalence (89%), low rates of clarithromycin and tetracycline resistance (1.7% and 2.5%, respectively), and a high rate of quinolone resistance (50%). CONCLUSION Therefore, the use of standard clarithromycin-based triple therapy is still possible as an empiric first-line treatment as well as prescription of bismuth-based quadruple therapy, which includes tetracycline, but not a levofloxacin-based triple therapy because of the high rate of resistance to fluoroquinolones.
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Affiliation(s)
| | | | - Rachelle Moyen
- Molecular and Cellular Biology Department, Technical and Sciences Faculty, Brazzaville, Congo
| | | | | | - O Obengui
- Microbiology and Haematology Department, Health Sciences Faculty, Brazzaville, Congo
| | | | - Etienne Nguimbi
- Molecular and Cellular Biology Department, Technical and Sciences Faculty, Brazzaville, Congo
| | - Rock Fabien Niama
- Molecular and Cellular Biology Department, Technical and Sciences Faculty, Brazzaville, Congo
| | - Jean Maurille Ouamba
- Chemistry plant and life unit, Technical and Sciences Faculty, Brazzaville, Congo
| | - Fidèle Yala
- Microbiology and Haematology Department, Health Sciences Faculty, Brazzaville, Congo
| | | | | | | | | | - Lucie Benejat
- French National Reference Center for Campylobacters and Helicobacters, University of Bordeaux, Bordeaux, France
| | - Elodie Sifre
- French National Reference Center for Campylobacters and Helicobacters, University of Bordeaux, Bordeaux, France
| | - Philippe Lehours
- INSERM U853, Bordeaux, France.,French National Reference Center for Campylobacters and Helicobacters, University of Bordeaux, Bordeaux, France
| | - Francis Megraud
- INSERM U853, Bordeaux, France.,French National Reference Center for Campylobacters and Helicobacters, University of Bordeaux, Bordeaux, France
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Dadashzadeh K, Milani M, Rahmati M, Akbarzadeh A. Real-time PCR detection of 16S rRNA novel mutations associated with Helicobacter pylori tetracycline resistance in Iran. Asian Pac J Cancer Prev 2015; 15:8883-6. [PMID: 25374223 DOI: 10.7314/apjcp.2014.15.20.8883] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tetracycline is an antibiotic widely used for the treatment of Helicobacter pylori infection, but its effectiveness is decreasing due to increasing bacterial resistance. The aim of this study was to investigate the occurrence of 16S rRNA mutations associated with resistance or reduced susceptibility to tetracycline of Helicobacter pylori by real-time PCR (RT-PCR) assays from culture. MATERIALS AND METHODS Tetracycline susceptibility and minimal inhibition concentration (MIC) was determined by the Epsilometer test (Etest) method. A LightCycler assay developed to detect these mutations was applied to DNA extracted from culture. The 16S rRNA of these isolates was sequenced and resistance-associated mutations were identified. From 104 isolates of H. pylori examined, 11 showed resistance to tetracycline. RESULTS LightCycler assay was applied to DNA extracted from 11 tetracycline-susceptible and 11 tetracycline resistance H. pylori isolates. In our study the sequencing of the H. pylori wild types in 16 s rRNA gene were AGA 926-928 with MIC (0.016 to 0.5 μg/ml), while the sequencing and MIC for resistant were GGA and AGC, (0.75 to 1.5 μg/ml), respectively. Also we found a novel mutation in 2 strains with 84° as their melting temperatures and exhibition of an A939C mutation. CONCLUSIONS We conclude that real-time PCR is an excellent method for determination of H. pylori tetracycline resistance related mutations that could be used directly on biopsy specimens.
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Affiliation(s)
- Kianoosh Dadashzadeh
- Department of Laboratory Sciences, Marand Branch, Islamic Azad University, Marand, Iran E-mail :
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Lupien A, Gingras H, Bergeron MG, Leprohon P, Ouellette M. Multiple mutations and increased RNA expression in tetracycline-resistant Streptococcus pneumoniae as determined by genome-wide DNA and mRNA sequencing. J Antimicrob Chemother 2015; 70:1946-59. [PMID: 25862682 DOI: 10.1093/jac/dkv060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/13/2015] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVES The objective of this study was to characterize chromosomal mutations associated with resistance to tetracycline in Streptococcus pneumoniae. METHODS Chronological appearance of mutations in two S. pneumoniae R6 mutants (R6M1TC-5 and R6M2TC-4) selected for resistance to tetracycline was determined by next-generation sequencing. A role for the mutations identified was confirmed by reconstructing resistance to tetracycline in a S. pneumoniae R6 WT background. RNA sequencing was performed on R6M1TC-5 and R6M2TC-4 and the relative expression of genes was reported according to R6. Differentially expressed genes were classified according to their ontology. RESULTS WGS of R6M1TC-5 and R6M2TC-4 revealed mutations in the gene rpsJ coding for the ribosomal protein S10 and in the promoter region and coding sequences of the ABC genes patA and patB. These cells were cross-resistant to ciprofloxacin. Resistance reconstruction confirmed a role in resistance for the mutations in rpsJ and patA. Overexpression of the ABC transporter PatA/PatB or mutations in the coding sequence of patA contributed to resistance to tetracycline, ciprofloxacin and ethidium bromide, and was associated with a decreased accumulation of [(3)H]tetracycline. Comparative transcriptome profiling of the resistant mutants further revealed that, in addition to the overexpression of patA and patB, several genes of the thiamine biosynthesis and salvage pathway were increased in the two mutants, but also in clinical isolates resistant to tetracycline. This overexpression most likely contributes to the tetracycline resistance phenotype. CONCLUSIONS The combination of genomic and transcriptomic analysis coupled to functional studies has allowed the discovery of novel tetracycline resistance mutations in S. pneumoniae.
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Affiliation(s)
- Andréanne Lupien
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Hélène Gingras
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Michel G Bergeron
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Philippe Leprohon
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Marc Ouellette
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
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16S rRNA gene mutations associated with decreased susceptibility to tetracycline in Mycoplasma bovis. Antimicrob Agents Chemother 2014; 59:796-802. [PMID: 25403668 DOI: 10.1128/aac.03876-14] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Mycoplasma bovis isolates with decreased susceptibilities to tetracyclines are increasingly reported worldwide. The acquired molecular mechanisms associated with this phenomenon were investigated in 70 clinical isolates of M. bovis. Sequence analysis of the two 16S rRNA-encoding genes (rrs3 and rrs4 alleles) containing the primary binding pocket for tetracycline (Tet-1 site) was performed on isolates with tetracycline hydrochloride MICs of 0.125 to 16 μg/ml. Mutations at positions A965T, A967T/C (Escherichia coli numbering) of helix 31, U1199C of helix 34, and G1058A/C were identified. Decreased susceptibilities to tetracycline (MICs, ≥2 μg/ml) were associated with mutations present at two (A965 and A967) or three positions (A965, A967, and G1058) of the two rrs alleles. No tet(M), tet(O), or tet(L) determinants were found in the genome of any of the 70 M. bovis isolates. The data presented correlate (P<0.0001) the mutations identified in the Tet-1 site of clinical isolates of M. bovis with decreased susceptibility to tetracycline.
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Negamycin interferes with decoding and translocation by simultaneous interaction with rRNA and tRNA. Mol Cell 2014; 56:541-50. [PMID: 25306922 DOI: 10.1016/j.molcel.2014.09.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 08/18/2014] [Accepted: 09/18/2014] [Indexed: 11/23/2022]
Abstract
Negamycin (NEG) is a ribosome-targeting antibiotic that exhibits clinically promising activity. Its binding site and mode of action have remained unknown. We solved the structure of the Thermus thermophilus ribosome bound to mRNA and three tRNAs, in complex with NEG. The drug binds to both small and large ribosomal subunits at nine independent sites. Resistance mutations in the 16S rRNA unequivocally identified the binding site in the vicinity of the conserved helix 34 (h34) in the small subunit as the primary site of antibiotic action in the bacterial and, possibly, eukaryotic ribosome. At this site, NEG contacts 16S rRNA as well as the anticodon loop of the A-site tRNA. Although the NEG site of action overlaps with that of tetracycline (TET), the two antibiotics exhibit different activities: while TET sterically hinders binding of aminoacyl-tRNA to the ribosome, NEG stabilizes its binding, thereby inhibiting translocation and stimulating miscoding.
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Mosquera-Rendón J, Cárdenas-Brito S, Pineda JD, Corredor M, Benítez-Páez A. Evolutionary and sequence-based relationships in bacterial AdoMet-dependent non-coding RNA methyltransferases. BMC Res Notes 2014; 7:440. [PMID: 25012753 PMCID: PMC4119055 DOI: 10.1186/1756-0500-7-440] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 07/02/2014] [Indexed: 12/12/2022] Open
Abstract
Background RNA post-transcriptional modification is an exciting field of research that has evidenced this editing process as a sophisticated epigenetic mechanism to fine tune the ribosome function and to control gene expression. Although tRNA modifications seem to be more relevant for the ribosome function and cell physiology as a whole, some rRNA modifications have also been seen to play pivotal roles, essentially those located in central ribosome regions. RNA methylation at nucleobases and ribose moieties of nucleotides appear to frequently modulate its chemistry and structure. RNA methyltransferases comprise a superfamily of highly specialized enzymes that accomplish a wide variety of modifications. These enzymes exhibit a poor degree of sequence similarity in spite of using a common reaction cofactor and modifying the same substrate type. Results Relationships and lineages of RNA methyltransferases have been extensively discussed, but no consensus has been reached. To shed light on this topic, we performed amino acid and codon-based sequence analyses to determine phylogenetic relationships and molecular evolution. We found that most Class I RNA MTases are evolutionarily related to protein and cofactor/vitamin biosynthesis methyltransferases. Additionally, we found that at least nine lineages explain the diversity of RNA MTases. We evidenced that RNA methyltransferases have high content of polar and positively charged amino acid, which coincides with the electrochemistry of their substrates. Conclusions After studying almost 12,000 bacterial genomes and 2,000 patho-pangenomes, we revealed that molecular evolution of Class I methyltransferases matches the different rates of synonymous and non-synonymous substitutions along the coding region. Consequently, evolution on Class I methyltransferases selects against amino acid changes affecting the structure conformation.
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Affiliation(s)
| | | | | | | | - Alfonso Benítez-Páez
- Bioinformatics Analysis Group - GABi, Centro de Investigación y Desarrollo en Biotecnología - CIDBIO, 111221 Bogotá, D,C, Colombia.
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An B, Moon BS, Lim HC, Lee YC, Kim H, Lee G, Kim SH, Park M, Kim JB. Analysis of Gene Mutations Associated with Antibiotic Resistance inHelicobacter pyloriStrains Isolated from Korean Patients. THE KOREAN JOURNAL OF HELICOBACTER AND UPPER GASTROINTESTINAL RESEARCH 2014. [DOI: 10.7704/kjhugr.2014.14.2.95] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Byoungrak An
- Department of Laboratory Medicine, Yongin Severance Hospital, Yongin, Korea
| | - Byung Soo Moon
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Hyun Chul Lim
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Yong Chan Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Heejung Kim
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Gyusang Lee
- Department of Biomedical Laboratory Science, College of Health Science, Yonsei University, Wonju, Korea
| | - Sa-Hyun Kim
- Department of Biomedical Laboratory Science, College of Health Science, Yonsei University, Wonju, Korea
| | - Min Park
- Department of Biomedical Laboratory Science, College of Health Science, Yonsei University, Wonju, Korea
| | - Jong Bae Kim
- Department of Biomedical Laboratory Science, College of Health Science, Yonsei University, Wonju, Korea
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Beceiro A, Tomás M, Bou G. Antimicrobial resistance and virulence: a successful or deleterious association in the bacterial world? Clin Microbiol Rev 2013; 26:185-230. [PMID: 23554414 PMCID: PMC3623377 DOI: 10.1128/cmr.00059-12] [Citation(s) in RCA: 626] [Impact Index Per Article: 56.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Hosts and bacteria have coevolved over millions of years, during which pathogenic bacteria have modified their virulence mechanisms to adapt to host defense systems. Although the spread of pathogens has been hindered by the discovery and widespread use of antimicrobial agents, antimicrobial resistance has increased globally. The emergence of resistant bacteria has accelerated in recent years, mainly as a result of increased selective pressure. However, although antimicrobial resistance and bacterial virulence have developed on different timescales, they share some common characteristics. This review considers how bacterial virulence and fitness are affected by antibiotic resistance and also how the relationship between virulence and resistance is affected by different genetic mechanisms (e.g., coselection and compensatory mutations) and by the most prevalent global responses. The interplay between these factors and the associated biological costs depend on four main factors: the bacterial species involved, virulence and resistance mechanisms, the ecological niche, and the host. The development of new strategies involving new antimicrobials or nonantimicrobial compounds and of novel diagnostic methods that focus on high-risk clones and rapid tests to detect virulence markers may help to resolve the increasing problem of the association between virulence and resistance, which is becoming more beneficial for pathogenic bacteria.
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Antimicrobial susceptibility and resistance patterns among Helicobacter pylori strains from The Gambia, West Africa. Antimicrob Agents Chemother 2012; 57:1231-7. [PMID: 23263004 DOI: 10.1128/aac.00517-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori is a globally important and genetically diverse gastric pathogen that infects most people in developing countries. Eradication efforts are complicated by antibiotic resistance, which varies in frequency geographically. There are very few data on resistance in African strains. Sixty-four Gambian H. pylori strains were tested for antibiotic susceptibility. The role of rdxA in metronidazole (Mtz) susceptibility was tested by DNA transformation and sequencing; RdxA protein variants were interpreted in terms of RdxA structure. Forty-four strains (69%) were resistant to at least 8 μg of Mtz/ml. All six strains from infants, but only 24% of strains from adults, were sensitive (P = 0.0031). Representative Mtz-resistant (Mtz(r)) strains were rendered Mtz susceptible (Mtz(s)) by transformation with a functional rdxA gene; conversely, Mtz(s) strains were rendered Mtz(r) by rdxA inactivation. Many mutations were found by Gambian H. pylori rdxA sequencing; mutations that probably inactivated rdxA in Mtz(r) strains were identified and explained using RdxA protein's structure. All of the strains were sensitive to clarithromycin and erythromycin. Amoxicillin and tetracycline resistance was rare. Sequence analysis indicated that most tetracycline resistance, when found, was not due to 16S rRNA gene mutations. These data suggest caution in the use of Mtz-based therapies in The Gambia. The increasing use of macrolides against respiratory infections in The Gambia calls for continued antibiotic susceptibility monitoring. The rich variety of rdxA mutations that we found will be useful in further structure-function studies of RdxA, the enzyme responsible for Mtz susceptibility in this important pathogen.
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Kupcinskas L, Rasmussen L, Jonaitis L, Kiudelis G, Jørgensen M, Urbonaviciene N, Tamosiunas V, Kupcinskas J, Miciuleviciene J, Kadusevicius E, Berg D, Andersen LP. Evolution ofHelicobacter pylorisusceptibility to antibiotics during a 10-year period in Lithuania. APMIS 2012; 121:431-6. [DOI: 10.1111/apm.12012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Accepted: 09/20/2012] [Indexed: 12/15/2022]
Affiliation(s)
- Limas Kupcinskas
- Institute for Digestive Research; Lithuanian University of Health Sciences; Kaunas; Lithuania
| | - Lone Rasmussen
- Department of Clinical Microbiology 9301; Copenhagen University Hospital; Rigshospitalet; Copenhagen; Denmark
| | - Laimas Jonaitis
- Institute for Digestive Research; Lithuanian University of Health Sciences; Kaunas; Lithuania
| | - Gediminas Kiudelis
- Institute for Digestive Research; Lithuanian University of Health Sciences; Kaunas; Lithuania
| | - Marianne Jørgensen
- Department of Clinical Microbiology 9301; Copenhagen University Hospital; Rigshospitalet; Copenhagen; Denmark
| | - Neringa Urbonaviciene
- Institute for Digestive Research; Lithuanian University of Health Sciences; Kaunas; Lithuania
| | - Vytas Tamosiunas
- Department of Biology; Faculty of Natural Sciences; Vilnius Pedagogical University; Vilnius; Lithuania
| | - Juozas Kupcinskas
- Institute for Digestive Research; Lithuanian University of Health Sciences; Kaunas; Lithuania
| | - Jolanta Miciuleviciene
- Institute for Digestive Research; Lithuanian University of Health Sciences; Kaunas; Lithuania
| | - Edmundas Kadusevicius
- Department of Basic and Clinical Pharmacology; Lithuanian University of Health Sciences; Kaunas; Lithuania
| | - Douglas Berg
- Department of Molecular Microbiology; Washington University Medical School; St. Louis; MO; USA
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Absence of Helicobacter pylori high tetracycline resistant 16S rDNA AGA926-928TTC genotype in gastric biopsy specimens from dyspeptic patients of a city in the interior of São Paulo, Brazil. BMC Gastroenterol 2012; 12:49. [PMID: 22594560 PMCID: PMC3449196 DOI: 10.1186/1471-230x-12-49] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 05/07/2012] [Indexed: 01/06/2023] Open
Abstract
Background Treatment effectiveness of Helicobacter pylori varies regionally and is decreasing worldwide, principally as a result of antibiotic resistant bacterium. Tetracycline is generally included in second line H. pylori eradication regimens. In Brazil, a high level of tetracycline resistance (TetR) is mainly associated with AGA926-928TTC 16 S rDNA nucleotide substitutions. As H. pylori culture is fastidious, we investigated the primary occurrence of H. pylori 16 S rDNA high level TetR genotype using a molecular approach directly on gastric biopsies of dyspeptic patients attending consecutively at Hospital das Clinicas of Marilia, São Paulo, Brazil. Methods Gastric biopsy specimens of 68 peptic ulcer disease (PUD) and 327 chronic gastritis (CG) patients with a positive histological diagnosis of H. pylori were investigated for TetR 16 S rDNA genotype through a molecular assay based on amplification of a 16 S rDNA 545 bp fragment by polymerase chain reaction and HinfI restriction fragment length polymorphism (PCR/RFLP). Through this assay, AGA926-928TTC 16 S rDNA TetR genotype resulted in a three DNA fragment restriction pattern (281, 227 and 37 bp) and its absence originated two DNA fragments (264 and 281 bp) due to a 16 S rDNA conserved Hinf I restriction site. Results The 545 bp 16 S rDNA PCR fragment was amplified from 90% of gastric biopsies from histological H. pylori positive patients. HinfI RFLP revealed absence of the AGA926–928TTC H. pylori genotype and PCR products of two patients showed absence of the conserved 16 S rDNA HinfI restriction site. BLASTN sequence analysis of four amplicons (two conserved and two with an unpredicted HinfI restriction pattern) revealed a 99% homology to H. pylori 16 S rDNA from African, North and South American bacterial isolates. A nucleotide substitution abolished the conserved HinfI restriction site in the two PCR fragments with unpredicted HinfI RFLP, resulting in an EcoRI restriction site. Conclusions H. pylori AGA926-928TTC 16 S rDNA gene substitutions were not found in our population. More research is required to investigate if H. pylori TetR has a different genetic background in our region and if the nucleotide substitutions of the uncultured H. pylori 16 S rRNA partial sequences have biological significance.
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Change in antibiotic resistance of Helicobacter pylori strains and the effect of A2143G point mutation of 23S rRNA on the eradication of H. pylori in a single center of Korea. J Clin Gastroenterol 2010; 44:536-43. [PMID: 20179610 DOI: 10.1097/mcg.0b013e3181d04592] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The current prevalence of primary antibiotic resistance of H. pylori is not known in Korea. This study was done to evaluate the prevalence of primary antibiotic resistance of H. pylori, and to evaluate the effect of point mutations of 23S rRNA on the rate of eradication of H. pylori. METHODS H. pylori were isolated from gastric mucosal biopsy specimens obtained from 222 Koreans. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, ciprofloxacin, and levofloxacin were examined using the agar dilution method. DNA sequencing was carried out to detect H. pylori 23S rRNA mutations. RESULTS The resistance to clarithromycin, tetracycline, ciprofloxacin, and levofloxacin increased during the period of 2007 to 2009 compared with 2003 to 2005 (P<0.05). However, amoxicillin and metronidazole resistance slightly decreased. The rates of eradication were 95.5% for the clarithromycin-sensitive strains, which was higher than the 67.9% for the clarithromycin-resistant strains (P=0.001). By contrast, the eradication rate was 100% in patients with amoxicillin-resistant H. pylori. Among 26 clarithromyin-resistant strains, 6 (23%) had A2143G mutations, and all of the cases in which these mutations were present were not eradicated by proton pump inhibitor-based triple therapy (P=0.0004). By contrast, none of the 26 clarithromyin-sensitive strains had A2143G mutations. The T2183C and A2223G mutations were frequently found in the sensitive strains and in the resistant strains. CONCLUSIONS Clarithromycin resistance of H. pylori, which determined the efficacy of H. pylori eradication of proton pump inhibitor triple regimen, was found to be increased in a single center study. A2143G was an important 23S rRNA mutation associated with clarithromycin resistance and affected the H. pylori eradication efficacy.
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Thaker M, Spanogiannopoulos P, Wright GD. The tetracycline resistome. Cell Mol Life Sci 2010; 67:419-31. [PMID: 19862477 PMCID: PMC11115633 DOI: 10.1007/s00018-009-0172-6] [Citation(s) in RCA: 212] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 09/24/2009] [Accepted: 10/05/2009] [Indexed: 11/27/2022]
Abstract
Resistance to tetracycline emerged soon after its discovery six decades ago. Extensive clinical and non-clinical uses of this class of antibiotic over the years have combined to select for a large number of resistant determinants, collectively termed the tetracycline resistome. In order to impart resistance, microbes use different molecular mechanisms including target protection, active efflux, and enzymatic degradation. A deeper understanding of the structure, mechanism, and regulation of the genes and proteins associated with tetracycline resistance will contribute to the development of tetracycline derivatives that overcome resistance. Newer generations of tetracyclines derived from engineering of biosynthetic genetic programs, semi-synthesis, and in particular recent developments in their chemical synthesis, together with a growing understanding of resistance, will serve to retain this class of antibiotic to combat pathogens.
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Affiliation(s)
- Maulik Thaker
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, 1200 Main St W, Hamilton, Canada
| | - Peter Spanogiannopoulos
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, 1200 Main St W, Hamilton, Canada
| | - Gerard D. Wright
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, 1200 Main St W, Hamilton, Canada
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Toledo H, Lopez-Solis R. Tetracycline resistance in Chilean clinical isolates of Helicobacter pylori. J Antimicrob Chemother 2009; 65:470-3. [DOI: 10.1093/jac/dkp457] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Anoushiravani M, Falsafi T, Niknam V. Proton motive force-dependent efflux of tetracycline in clinical isolates of Helicobacter pylori. J Med Microbiol 2009; 58:1309-1313. [PMID: 19574414 DOI: 10.1099/jmm.0.010876-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The aim of this study was to evaluate the role of proton motive force (PMF)-dependent efflux in resistance of Helicobacter pylori to tetracycline (Tet). Tet MIC was determined by agar dilution in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP), an inhibitor of PMF. Antibiotic accumulation was conducted in the presence or absence of CCCP and the fluorescence of the accumulated antibiotic was measured by spectrofluorometry. In the presence of CCCP, antibiotic accumulation was increased by 2-17-fold in 17/20 Tet(r) isolates and by 3-10-fold in four of five high-level-resistant mutants. Correlation was observed between this increase and diminution of MIC with CCCP. PMF-dependent efflux mechanisms therefore appear to play an important role in the resistance of clinical isolates of H. pylori to Tet.
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Affiliation(s)
| | | | - Vahid Niknam
- Department of Biology, Tehran University, Tehran, Iran
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Khan R, Nahar S, Mukhopadhyay AK, Berg DE, Ahmad MM, Okamoto K, Nair GB, Rahman M. Isolation of tetracycline-resistant clinicalHelicobacter pyloriwithout mutations in 16S rRNA gene in Bangladesh. Microbiol Immunol 2008; 52:508-11. [DOI: 10.1111/j.1348-0421.2008.00062.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Jones KR, Cha JH, Merrell DS. Who's Winning the War? Molecular Mechanisms of Antibiotic Resistance in Helicobacter pylori. CURRENT DRUG THERAPY 2008; 3:190-203. [PMID: 21765819 DOI: 10.2174/157488508785747899] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The ability of clinicians to wage an effective war against many bacterial infections is increasingly being hampered by skyrocketing rates of antibiotic resistance. Indeed, antibiotic resistance is a significant problem for treatment of diseases caused by virtually all known infectious bacteria. The gastric pathogen Helicobacter pylori is no exception to this rule. With more than 50% of the world's population infected, H. pylori exacts a tremendous medical burden and represents an interesting paradigm for cancer development; it is the only bacterium that is currently recognized as a carcinogen. It is now firmly established that H. pylori infection is associated with diseases such as gastritis, peptic and duodenal ulceration and two forms of gastric cancer, gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. With such a large percentage of the population infected, increasing rates of antibiotic resistance are particularly vexing for a treatment regime that is already fairly complicated; treatment consists of two antibiotics and a proton pump inhibitor. To date, resistance has been found to all primary and secondary lines of antibiotic treatment as well as to drugs used for rescue therapy.
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Affiliation(s)
- Kathleen R Jones
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814, USA
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He H, Wang HM, Chi J. Detection of the drug-resistant gene of Helicobacter pylori. Shijie Huaren Xiaohua Zazhi 2008; 16:510-516. [DOI: 10.11569/wcjd.v16.i5.510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Antibiotic-resistant Helicobacter pylori (H. pylori) and the resistance rate are increased due to the wide use of antibiotics. At present, the detection of antibiotic-resistant H. pylori is focused on the clarithromycin and metronidazole resistance testing using PCR-based molecular biology techniques. However, PCR-restriction fragment length polymorphism and real-time PCR in combination with melting curve analysis techniques have a broad prospect in detecting drug-resistant clarithromycin. They can detect it from tissue biopsy and stool samples, and thus can be used in detecting the resistance of a wide range of antibiotics. Western blot and PCR- restriction fragment length polymorphism can also detect the resistance of metronidazole, and can therefore develop into the routine procedures for detecting drug-resistant H. pylori.
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Saraiya AA, Lamichhane TN, Chow CS, SantaLucia J, Cunningham PR. Identification and role of functionally important motifs in the 970 loop of Escherichia coli 16S ribosomal RNA. J Mol Biol 2007; 376:645-57. [PMID: 18177894 DOI: 10.1016/j.jmb.2007.11.102] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 11/26/2007] [Accepted: 11/30/2007] [Indexed: 10/22/2022]
Abstract
The 970 loop (helix 31) of Escherichia coli 16S ribosomal RNA contains two modified nucleotides, m(2)G966 and m(5)C967. Positions A964, A969, and C970 are conserved among the Bacteria, Archaea, and Eukarya. The nucleotides present at positions 965, 966, 967, 968, and 971, however, are only conserved and unique within each domain. All organisms contain a modified nucleoside at position 966, but the type of the modification is domain specific. Biochemical and structure studies have placed this loop near the P site and have shown it to be involved in the decoding process and in binding the antibiotic tetracycline. To identify the functional components of this ribosomal RNA hairpin, the eight nucleotides of the 970 loop of helix 31 were subjected to saturation mutagenesis and 107 unique functional mutants were isolated and analyzed. Nonrandom nucleotide distributions were observed at each mutated position among the functional isolates. Nucleotide identity at positions 966 and 969 significantly affects ribosome function. Ribosomes with single mutations of m(2)G966 or m(5)C967 produce more protein in vivo than do wild-type ribosomes. Overexpression of initiation factor 3 specifically restored wild-type levels of protein synthesis to the 966 and 967 mutants, suggesting that modification of these residues is important for initiation factor 3 binding and for the proper initiation of protein synthesis.
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Affiliation(s)
- Ashesh A Saraiya
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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Abstract
The ribosome is responsible for protein synthesis, the translation of the genetic code, in all living organisms. Ribosomes are composed of RNA (ribosomal RNA) and protein (ribosomal protein). Soluble protein factors bind to the ribosome and facilitate different phases of translation. Genetic approaches have proved useful for the identification and characterization of the structural and functional roles of specific nucleotides in ribosomal RNA and of specific amino acids in ribosomal proteins and in ribosomal factors. This chapter summarizes examples of mutations identified in ribosomal RNA, ribosomal proteins, and ribosomal factors.
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MESH Headings
- Animals
- Base Sequence
- DNA Mutational Analysis
- Humans
- Mutation
- Nucleic Acid Conformation
- Peptide Elongation Factors/genetics
- Peptide Initiation Factors/genetics
- Peptide Termination Factors/genetics
- Protein Subunits/genetics
- RNA, Ribosomal, 16S/analysis
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/physiology
- RNA, Ribosomal, 23S/analysis
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/physiology
- Ribosomal Proteins/genetics
- Ribosomes/genetics
- Sequence Analysis, RNA
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Affiliation(s)
- Kathleen L Triman
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17604, USA
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44
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Mégraud F, Lehours P. Helicobacter pylori detection and antimicrobial susceptibility testing. Clin Microbiol Rev 2007; 20:280-322. [PMID: 17428887 PMCID: PMC1865594 DOI: 10.1128/cmr.00033-06] [Citation(s) in RCA: 464] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The discovery of Helicobacter pylori in 1982 was the starting point of a revolution concerning the concepts and management of gastroduodenal diseases. It is now well accepted that the most common stomach disease, peptic ulcer disease, is an infectious disease, and all consensus conferences agree that the causative agent, H. pylori, must be treated with antibiotics. Furthermore, the concept emerged that this bacterium could be the trigger of various malignant diseases of the stomach, and it is now a model for chronic bacterial infections causing cancer. Most of the many different techniques involved in diagnosis of H. pylori infection are performed in clinical microbiology laboratories. The aim of this article is to review the current status of these methods and their application, highlighting the important progress which has been made in the past decade. Both invasive and noninvasive techniques will be reviewed.
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Affiliation(s)
- Francis Mégraud
- INSERM U853, and Université Victor Segalen Bordeaux 2, and Laboratoire de Bactériologie, Hôpital Pellegrin, Place Amélie Raba-Léon, 33076 Bordeaux cedex, France.
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45
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Abstract
The emergence of mutations in nucleic acids is one of the major factors underlying evolution, providing the working material for natural selection. Most bacteria are haploid for the vast majority of their genes and, coupled with typically short generation times, this allows mutations to emerge and accumulate rapidly, and to effect significant phenotypic changes in what is perceived to be real-time. Not least among these phenotypic changes are those associated with antibiotic resistance. Mechanisms of horizontal gene spread among bacterial strains or species are often considered to be the main mediators of antibiotic resistance. However, mutational resistance has been invaluable in studies of bacterial genetics, and also has primary clinical importance in certain bacterial species, such as Mycobacterium tuberculosis and Helicobacter pylori, or when considering resistance to particular antibiotics, especially to synthetic agents such as fluoroquinolones and oxazolidinones. In addition, mutation is essential for the continued evolution of acquired resistance genes and has, e.g., given rise to over 100 variants of the TEM family of beta-lactamases. Hypermutator strains of bacteria, which have mutations in genes affecting DNA repair and replication fidelity, have elevated mutation rates. Mutational resistance emerges de novo more readily in these hypermutable strains, and they also provide a suitable host background for the evolution of acquired resistance genes in vitro. In the clinical setting, hypermutator strains of Pseudomonas aeruginosa have been isolated from the lungs of cystic fibrosis patients, but a more general role for hypermutators in the emergence of clinically relevant antibiotic resistance in a wider variety of bacterial pathogens has not yet been proven.
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Affiliation(s)
- N Woodford
- Antibiotic Resistance Monitoring and Reference Laboratory, Centre for Infections, Health Protection Agency, London, UK.
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46
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Gerrits MM, van Vliet AHM, Kuipers EJ, Kusters JG. Helicobacter pylori and antimicrobial resistance: molecular mechanisms and clinical implications. THE LANCET. INFECTIOUS DISEASES 2006; 6:699-709. [PMID: 17067919 DOI: 10.1016/s1473-3099(06)70627-2] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Helicobacter pylori is an important human pathogen that colonises the stomach of about half of the world's population. The bacterium has now been accepted as the causative agent of several gastroduodenal disorders, ranging from chronic active gastritis and peptic ulcer disease to gastric cancer. The recognition of H pylori as a gastric pathogen has had a substantial effect on gastroenterological practice, since many untreatable gastroduodenal disorders with uncertain cause became curable infectious diseases. Treatment of H pylori infection results in ulcer healing and can reduce the risk of gastric cancer development. Although H pylori is susceptible to many antibiotics in vitro, only a few antibiotics can be used in vivo to cure the infection. The frequent indication for anti-H pylori therapy, together with the limited choice of antibiotics, has resulted in the development of antibiotic resistance in H pylori, which substantially impairs the treatment of H pylori-associated disorders. Antimicrobial resistance in H pylori is widespread, and although the prevalence of antimicrobial resistance shows regional variation per antibiotic, it can be as high as 95%. We focus on the treatment of H pylori infection and on the clinical relevance, mechanisms, and diagnosis of antimicrobial resistance.
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Affiliation(s)
- Monique M Gerrits
- Department of Gastroenterology and Hepatology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, Netherlands
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47
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Li Y, Dannelly HK. Inactivation of the putative tetracycline resistance gene HP1165 in Helicobacter pylori led to loss of inducible tetracycline resistance. Arch Microbiol 2006; 185:255-62. [PMID: 16482431 DOI: 10.1007/s00203-006-0093-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 01/17/2006] [Accepted: 01/17/2006] [Indexed: 12/11/2022]
Abstract
Tetracycline has been used with other antibiotics in treatment of Helicobacter pylori infection. However, tetracycline resistance has developed in H. pylori clinical isolates, rendering treatment failure. Mutations in 16S rRNA genes have been reported to mediate tetracycline resistance in some isolates. The diversity of tetracycline resistance cases suggests multiple genes are involved. HP1165, a putative tetracycline resistance gene in H. pylori 26695, displays 49.8% identity to the tetracycline efflux gene tetA (P) from Clostridium perfringens. To determine the function of the HP1165 gene in H. pylori, the tetracycline resistance phenotype was investigated, transcription of HP1165 was examined by RT-PCR, and a DeltaHP1165 mutant was generated by insertion of the pBCalpha3 plasmid. The results showed that strains harboring HP1165 were induced to intermediate level resistance in the laboratory (minimum inhibitory concentration=4-6 microg/ml). No mutation was found at or near the tetracycline binding sites of the 16S rRNA gene. The gene was transcribed both in the induced tetracycline resistant and wild type strains, indicating translational or posttranslational control of gene function. Mutation of HP1165 gene resulted in increased tetracycline susceptibility and loss of inducible tetracycline resistance, suggesting that the HP1165 gene is involved in the inducible tetracycline resistance in H. pylori.
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Affiliation(s)
- Yuhuan Li
- Department of Life Sciences, Indiana State University, 6th and Chestnut Streets, Terre Haute, IN 47809, USA
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48
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Binet R, Maurelli AT. Fitness cost due to mutations in the 16S rRNA associated with spectinomycin resistance in Chlamydia psittaci 6BC. Antimicrob Agents Chemother 2006; 49:4455-64. [PMID: 16251283 PMCID: PMC1280162 DOI: 10.1128/aac.49.11.4455-4464.2005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The fitness cost of a resistance determinant is the primary parameter that determines its frequency in vivo. As a model for analysis of the impact of drug resistance mutations on the intracellular life cycle of Chlamydia spp., we studied the growth of four genetically defined spectinomycin-resistant (Spc(r)) clonal variants of Chlamydia psittaci 6BC isolated in the plaque assay. The development of each variant was monitored over 46 h postinfection in the absence of drug, either in pure culture or in 1:1 competition with the parent strain. Spc(r) mutations in the 16S rRNA gene at positions 1191 and 1193 were associated with a marked impairment of C.psittaci biological fitness, and the bacteria were severely out-competed by the wild-type parent. In contrast, mutations at position 1192 had minor effects on the bacterial life cycle, allowing the resistant isolates to compete more efficiently with the wild-type strain. Thus, mutations with a wide range of fitness costs can be selected in the plaque assay, providing a new strategy for prediction and monitoring of the emergence of antibiotic resistance in chlamydiae. So far, drug resistance has not been a serious threat for the treatment of chlamydial infections. Tetracycline is an effective antichlamydial drug that targets 16S rRNA. Attempts to isolate spontaneous tetracycline-resistant mutants of C. psittaci 6BC revealed a frequency <3 x 10(-9). We suggest that the rarity of genotypic antibiotic resistance among chlamydial clinical isolates reflects the deleterious effects of such mutations on the fitness of these obligate intracellular bacteria in the host.
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Affiliation(s)
- Rachel Binet
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814-4799, USA
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49
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Glocker E, Berning M, Gerrits MM, Kusters JG, Kist M. Real-time PCR screening for 16S rRNA mutations associated with resistance to tetracycline in Helicobacter pylori. Antimicrob Agents Chemother 2005; 49:3166-70. [PMID: 16048919 PMCID: PMC1196286 DOI: 10.1128/aac.49.8.3166-3170.2005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The effectiveness of recommended first-line therapies for Helicobacter pylori infections is decreasing due to the occurrence of resistance to metronidazole and/or clarithromycin. Quadruple therapies, which include tetracycline and a bismuth salt, are useful alternative regimens. However, resistance to tetracycline, mainly caused by mutations in the 16S rRNA genes (rrnA and rrnB) affecting nucleotides 926 to 928, are already emerging and can impair the efficacies of such second-line regimens. Here, we describe a novel real-time PCR for the detection of 16S rRNA gene mutations associated with tetracycline resistance. Our PCR method was able to distinguish between wild-type strains and resistant strains exhibiting single-, double, or triple-base-pair mutations. The method was applicable both to DNA extracted from pure cultures and to DNA extracted from fresh or frozen H. pylori-infected gastric biopsy samples. We therefore conclude that this real-time PCR is an excellent method for determination of H. pylori tetracycline resistance even when live bacteria are no longer available.
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Affiliation(s)
- Erik Glocker
- Nationales Referenzzentrum für Helicobacter pylori, Abteilung Medizinische Mikrobiologie und Hygiene, Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Freiburg, Hermann-Herder-Strasse 11, D-79104 Freiburg, Germany
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50
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Morris JM, Reasonover AL, Bruce MG, Bruden DL, McMahon BJ, Sacco FD, Berg DE, Parkinson AJ. Evaluation of seaFAST, a rapid fluorescent in situ hybridization test, for detection of Helicobacter pylori and resistance to clarithromycin in paraffin-embedded biopsy sections. J Clin Microbiol 2005; 43:3494-6. [PMID: 16000488 PMCID: PMC1169084 DOI: 10.1128/jcm.43.7.3494-3496.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A commercially available rapid fluorescent in situ hybridization (FISH) test, (seaFAST H. pylori Combi-Kit; SeaPro Theranostics International, Lelystad, The Netherlands) was used to simultaneously detect the presence of Helicobacter pylori and determine clarithromycin susceptibility in paraffin-embedded biopsy sections. The FISH method was found to be 97% sensitive, 94% specific for the detection of H. pylori and comparable to agar dilution for the detection of resistance to clarithromycin.
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Affiliation(s)
- Julie M Morris
- Arctic Investigations Program, CDC, 4055 Tudor Centre Drive, Anchorage, AK 99508, USA.
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